Investigation of microstructure and corrosion resistance of silumin after nickel and copper addition

Aluminium whose Silicon as its main alloying element, i.e. Silumin, is widely applied in engineering due to its novel properties. For particular application, e.g. as block engine of seawater vessel, Silumin’s properties must be enhanced, e.g. strength at elevated temperature, hardenability and corrosion resistance. For those purposes, Nickel and Copper is added to Silumin in this work. As a result, Copper addition by 4.1 %wt increases Silumin density by 13.9 % from 2.95 to 3.36 g/cm3, decreases grain size by 35.3 % from 39.4 to 25.5 μm, increases hardness by 178.8 % from 21.66 to 60.38 HR30T and increases the corrosion rate by 24.5 % from 0.354 to 0.441 mmpy. Meanwhile, addition of Nickel by 6.35 %wt increases Silumin density by 14.9 % from 2.95 to 3.39 g/cm3, decreases grain size by 29.7 % from 39.4 to 27.7 μm, increases hardness by 161.8 % from 21.66 to 56.71 HR30T and decreases the corrosion rate by 41.2 % from 0.354 to 0.2211 mmpy. To investigate the influence of Copper and Nickel addition on Silumin’s microstructure, micrograph is also taken by using an optical microscope and a scanning electron microscope. The micrograph shows dendrite presence only for the case of Copper added Silumin which deleterious for mechanical properties of Silumin. This dendrite is predicted due to slower cooling rate of the cast Silumin after Copper addition. In addition, the needle-like β-precipitate is sharper after Copper addition. This circumstance is responsible for higher hardness increase for the case of Copper addition compared to Nickel addition. The micrograph shows the existence of CuAl2 intermetallic phase. This intermetallic phase is nobler than Aluminium which is responsible for higher galvanic corrosion in Silumin after Copper addition. On the other hand, the dendrite cannot be observed in the case of Silumin after Nickel addition. The intermetallic phases after Nickel addition, i.e. AlxNiy contribute to the hardness increase. These phases also remain stable at elevated temperature which then then contributes to better mechanical properties of Silumin at the elevated temperatur

PEMILIHAN KEPUTUSAN PENGGUNAAN SODA API (NaOH) SEBAGAI ALTERNATIF PENGGANTI THINNER CAIRAN PEMBERSIH CAT PADA LOGAM DENGAN MENGGUNAKAN METODE Analityc Network Process (ANP)

Many Indonesians still use Thinner as paint cleaner solution. Thinner is a compound of petroleum. Petroleum is a non-renewable natural resource. Under these conditions, alternatives are needed that can be used either to replace or reduce the use of thinner. The alternative to use chemicals is caustic soda (NaOH). The criterion and sub-criteria which is to know the priority of use in choosing cleaning fluid of paint chemical obtained by conducting interview with user of caustic and thinner liquid to clean paint. The result of the interview is processed into questionnaires and calculated using ANP obtained 5 criteria (Economics, Environment, Technical, Concentration and Time) and 10 sub- criteria. Decision-making alternative to thinner cleaning paint alternator using ANP method gives higher priority value of caustic soda that is 0.67617 or 67.6% compared with thinner priority value of 0.392383 or 39.3%. So caustic soda is an alternative  liquid  to  replace  the  thinner  as  a  cleaning  fluid.  The  optimal concentration of liquid caustic soda (NaOH) is 187.5 M with a mixture of 150 grams of water with a volume of water / aquades of 20 ml resulting in a 10-minute peel time

Metallurgical Analysis of Steel Plate for Deep Drawing Application

Deep drawing is one of metal forming manufacturing processes which can be used to produce many products, e.g. kitchen ware, automotive parts, etc. Although this particular manufacturing company has applied the Japanese standard JIS G 3141 as guidance to select a steel plate for deep drawing application, the deep drawing process at this company is still failed. Therefore, this manuscript discusses more deeply the metallurgical analysis of selected steel plates to produce a deep-drawn product with 0.5 thickness. Analysis presented in this manuscript comprises the influence of chemical composition of a steel plate on its mechanical property, i.e., tensile strength, elongation, and hardness. As a result, a correlation between chemical compo­sition and expected mechanical property to manufacture a drink cup is outlined. Moreover, recommended chemical composition of a steel plate is also presented

Информационная система технического сервиса машинотракторного парка

Предоставление услуг технического сервиса требует предоставления гарантий качества этих услуг. Результаты исследований ведущих специалистов в этой области не всегда доступны инженерам сельскохозяйственных предприятий, поэтому существует необходимость в разработке методик оценки качества клиентом или подтверждения обеспечения качества поставщиком услуг технического сервиса. Проект системы технического сервиса машинотракторного парка, включающей в себя совокупность взаимосвязанных и взаимообусловленных ее элементов - процессов, происходящих в машинах; технологий технического сервиса; исполнителей технического сервиса - определяемую и направляемую целью технического сервиса - поддержание работоспособности сельскохозяйственной техники, позволяет сформировать методику оценки качества. Показатель качества представляет собой произведение частных коэффициентов, учитывающих степень соответствия выполненных объемов работ требуемым объемам; степень соответствия периодичности ТО требуемым значениям; степень соответствия технологий ТО и ремонта процессам в подсистемах; достаточность компетенций исполнителей для реализации технологий ТО и ремонта; достаточность перечня работ, потенциально выполняемых исполнителями технического сервиса, для обслуживания определенного вида машинотракторных агрегатов. Степень соответствия периодичности может обеспечиваться соблюдением требований нормативно-технической документации. Объемы работ технического сервиса могут быть обеспечены работой группы исполнителей технического сервиса. Предлагается вариант методики оценки компетенций исполнителей технического сервиса. Вместе с тем разработанная информационная система технического сервиса позволяет выявить взаимосвязи, определяющие качество технического сервиса.Providing technical services also requires providing quality assurance of these services. Results of leading experts' research in this field is not always available for engineers of agricultural companies, that is why there is need for development of a customer quality assessment method or a method of quality assurance by technical services suppliers. Project of machines and tractor fleet technical service system which included an assembly of interrelated and interdependent elements - processes running in machines, technologies of technical service, performers of technical service - is defined and directed by the aim of technical service which consists in maintaining operability of agricultural equipment, allows to create a method of quality assessment. The quality index represents multiplication of partial factors which take into consideration degree of correspondence of performed volume of works to the required volume, degree of correspondence of maintenance intervals to the required intervals, degree of conformity of repair and maintenance technologies to processes in subsystems; sufficiency of performers competence for implementation of repair and maintenance; sufficiency of range of works potentially carried out by technical service performers for maintenance of a certain types of machine- and tractor aggregates. The degree of correspondence of intervals can be ensured by meeting the requirements of standards and technical documentation. The volume of technical services works can be provided by involving a group of technical service performers. A variant of technical service performers' competence assessment method is suggested. Along with that an information system of technical service is developed which allows to state interdependencies determining quality of technical service

Капитальный ремонт магистрального нефтепровода в условиях болотистой местности

Объектом исследования является ремонтируемый участок магистрального трубопровода "Александровское – Анжеро-Судженск", находящийся на 282 км трассы и проходящий через болота II типа. Цель работы – Проведение капитального ремонта магистрального нефтепровода методом вырезки/врезки катушки в условиях болот. В процессе исследования проводились расчеты эксплуатационных затрат на ремонт врезкой катушки и ремонт композитной муфтой, а также расчеты трубопровода на прочность, деформативность, общую устойчивость в продольном направлении к различным нагрузкам и воздействиям, в данном случае эксплуатация трубопровода в условиях болотистой местности и устойчивость против всплытия.The object of the research is the repaired section of the Aleksandrovskoye - Anzhero-Sudzhensk trunk pipeline, which is located on the 282 km of the route and passes through type II swamps. The purpose of the work is to carry out the overhaul of the main oil pipeline by cutting / tapping the coil in wetland conditions. In the course of the study, calculations were made of the operating costs for repairing the coil insert and repair with a composite coupling, as well as calculations of the pipeline for strength, deformability, and overall resistance in the longitudinal direction to various loads and impacts, in this case, the operation of the pipeline in wetland conditions and resistance to ascent

St. John's Daily Star, 1919-03-15

The St. John's Daily Star was published daily except Sunday between 17 April 1915 - 23 July 1921

Strategy to Improve Recycling Yield of Aluminium Cans

Millions of canned drinks are consumed everyday globally and their wastes create an enviromental issue. Fortunately, the cans are made from aluminium (Al) so that it can be recycled. There are two main keypoints existing during the recycling process of Al cans, i.e. the aluminium loss or low Al-yield and low recycling yield. This work outlines the strategies to improve the recycling perfomance for Al beverage cans, i.e. by adding drossing flux, applying improved melting strategy, and cans decoating prior to melting. Drossing flux was added to assist the detachment of Al from the slag. Another improved melting strategy was worked out by decreasing exposure time cans to the furnace atmosphere during melting. All those above strategies result in an increase of recycle yield in a range of 4 % to 5 %